Shield for vacuum cleaner belt guards



Dec. 2, 1952 F, s, HOWARD 2,619,670

SHIELD FOR VACUUM CLEANER BELT GURDS Filed Feb. 2. 1946 Patentedv Dec. 2, 19j52 SHIELD FOR VACUUM CLEANER BELT GUARDS Frank S. Howard, Chicago, 111.', assignor to Birtman Electric Company, a corporation of Illinois i Application February 2, 1946, Serial No. 645,103

2 Claims. (Cl. 15-391) This invention relates to a vacuum cleaner, and particularly to a shield to prevent foreign matter such as threads, hair, and the like from winding around the suction fan shaft.

Belt guards are often used on vacuum cleaners to protect the belt which drives the rotatable brush. The belt guard serves to prevent dirt, threads, and the like in the air stream from contacting the belt and causing it to wear. It has been found that in actual practice threads and hair sometimes enter the opening at the top of the belt guard that is usually positioned around the shaft that drives the belt and become wound around the shaft and wedged so as to necessitate removal of the belt guard in order to clean out the threads and hair. The present invention provides a shield for this area so that the above will not take place. With this new shield dirtladen air is drawn through the cleaner into the fan chamber, and out into the dust collecting bag without any threads, hair, or the like becoming wound around the shaft and wedged between the shaft, the belt guard and the fan hub.

The invention will be described as related to the embodiment shown in the accompanying drawing, which is an elevation of a vacuum cleaner embodying the invention, with portions broken away for clarity of illustration.

The vacuum cleaner shown in the accompanying drawing comprises a casing I0, a handle II, a rotatable brush I2 for contacting the work to be cleaned, a motor I3 mounted within the casing with its shaft I4 in substantially vertical position, a fan I5, a fan chamber I6, an outlet passageway I1 from the fan chamber, and a belt I8 driven by the motor shaft and driving the rotatable brush. The belt I8 is held on a spindle I9 attached to and concentric with the bottom of the motor shaft I4. There is also provided a belt guard 20 surrounding the belt I8 and the spindle I9.

In order that threads, hair, and the like will be prevented from entering around the belt guard 20 and winding around the shaft, there is provided a shield at the area where the belt guard adjoins the fan hub 2|. This shield is located in an annular recess 22 in the fan hub 2I and substantially concentric with the motor shaft I4. This recess is provided with substantially parallel sides and fiat bottom portion. The shield comprises an extension 23 provided at the top of the belt guard surrounding the motor shaft I4, with this extension being integral with the belt guard 20. The extension is substantially circular in cross-section, and has its open end within the recess 22 and adjacent the bottom of the recess. Between the open end of the extension 23 and the bottom of the recess 22. there is located a soft Wear-resistant closure member such as a felt washer '24. The fan I5 and the recess 22 are rotated by the motor shaft I4, while the belt guard extension 23 remains stationary. If the shield were not provided there would be a suction created Within the belt guard 20, and this would tend to draw threads, hair, and similar foreign matter into the belt guard, Where they would wind around the shaft. The shield, however, successfully prevents this, and all foreign matter is carried into the fan chamber I6 and out the exit passageway Il.

Although the shield is preferably provided with a felt washer 24, or other closure member, this may be dispensed with if desired, and the extension 23 may be extended to a point closely adjacent the bottom surface of the recess 22. Even without the closure member the shield is efficient in operation.

There is also preferably provided a small hole 25 in the bottom plate 26 of the vacuum cleaner, which also forms the bottom of the belt guard 20. This hole serves to bleed air into the belt guard and relieve the suction therein. When the cleaner is in operation there is a suction built up in the belt guard as a result of small leakages of air around the fan spindle and around that portion of the rotatable brush adjacent the belt guard. This causes dirt-laden air to be drawn into the belt guard. The small hole 25 relieves this suction and causes air to flow in the hole 25 and out around the fan spindle and the rotatable brush so that no dirt can enter the belt guard. The hole 25 is preferably placed under the belt spindle I9. The size of the bleed hole 25 depends on the vacuum within the belt guard. Usually the hole should not be greater than 1/4 inch in diameter, and in one embodiment was about inch in diameter. The hole should preferably be located at some point away from the dirt-laden air stream, and, as shown, is located opposite the bottom end of the belt shaft I9.

In my copending application Serial No. 645,102, filed February 2, 1946, and now abandoned, I have disclosed and claimed the means for relieving the Vacuum within the belt guard 20 here shown as the small opening 25 in the belt iaiic and located beneath the end of the spin- Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description unless otherwise specied, but rather be construed broadly within its spirit and scope as set, out in the accompanying claims.

Iclaim:

1. In a vacuum cleaner including a body, a nozzle in the cleaner body, a rotatable brush in the nozzle, a lfan shaft rotatably supported in the cleaner body and a centrifugal fan including a fan hub xed to the shaft, a thread shield for the shaft comprising a tubular member surrounding the outer end of the `fan shaft 'cen'- trally of the fan blades and having one end eX- tending into an annular recess in the `fan hub,

and a soft wear-resistant closure member .'p'osi' tioned between this extending end and a Wall of the recess, the edge of the fan =hub defining the outer margin of the recess being spaced outwardly and extending beyond the end of the tubular member within the recess in over-lapping relationship to shield the closure member from lthe fan air-stream.

2. The vacuum cleaner of claim 1 wherein the closure member is located between said end of the tubular memberand the .bottom of the recess.

FRANKS. HOWARD.

4 REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS OTHER REFERENCES Product Engineering, Advertisement by ArmstrongCo., page 62, Sept. 1942. (Copy in Division 52.) 

